im switching all my sram stuff to shimano XTR for next season. I have a few questions regarding some XTR components, I am very unfamiliar with shimano overall. Keep in mind I will be riding a sram crankset though. Everything else will be shimano.

1- the XTR m985 brakes: are they powerful enough to run a 140mm rotor at the back on my 29er hardtail? I am 150-155 lbs.

2- the XTR shadow plus rear der: does it require any special maintenance? Any regular check up to make sure it functions properly?

3- any real benefits to a XTR front derailleur over a XT front derailleur other then weight?

4- finally, what chain do you guys generally run with a shimano drivetraing. I have read some people tend to avoid the shimano chains...

1 - Depends what rotors you are running - IceTech's shouldn't be a problem for XC racing. Personally I would stick to 160/160 because if you need to borrow a wheel from someone that is most common.

2 - The only 'maintenance' my XTR shadow+ got all season was when washing it, and I would use a screwdriver to clean any gunk off the pulley wheels. Out of sheer boredom one day I overhauled the pulley wheel bearings but they were mint, even after many muddy rides. You DO however have to pay more attention to the cables and housing, because of the extra friction of the clutch. Highly recommend sticking to XTR housing and cables. Buy some bulk SP41 housing and change housing whenever you feel it's getting stiffer - I used the same cable all season, the coating never wore off and when I'd replace the housing (about 6 times this race season) I'd give it a good wipe down and it was good as new.

1, yes, tho really, there's little/no point. Weight saving is negligible, running 160s both ends will give you less spares to carry and easy interchangeablity. I've standardised on 180/160, so I can use all my wheels on all my bikes with an absolute minimum of fuss. (One pair need the calipers centering if I use them)Some frames won't take a 140 either.

3, weight, that's about it. They seem to last longer, but it's a front mech, they last for ages anyway. Functionally, I can't tell the difference.

4, every shimano chain I've ever had has broken prematurely, either fitted myself, factory fitted or by a shimano service tech (at a race site) they used to go within 10-14 days. I tend to use KMC or wippermann/connex now. (I haven't used a shimano chain for about 10 years, so they might be better now.)

Joined: Mon Jan 10, 2005 10:47 amPosts: 939Location: somewere floating between here and the other side

I would run an xtr chain and casette, i dont think anything else would shift anywhere near as smooth.Chains, regardless of make only break because of poor workmanship.a propper mounted chain doesn't fail.

I've used XTR, X10SL, and PG1091 chains with an otherwise m980 setup, all shifted exactly the same, however, the XTR chain broke after less than 200 miles. Replaced it with another XTR chain which failed in a similar manner and time frame. Since then I've used KMC X10SL chains up until July when I had to replace it while on vacation (I stopped keeping track of it, and it ended up being completely worn when I got there) with a PG1091. I never had any problems with the KMC, and I have yet to have any issues with the Sram chain.

I went XTR 980 (Trail Double crank) from SRAM XX this year and I like it much, much better in many ways. Using Hope breaks though so I can't comment on your rotor question.

Regarding chains; I really liked the XTR chain I started the season on. I measure chain wear pretty regularly and I was impressed with how slowly it was wearing as the season progressed. I eventually swapped it out for a KMC that lasted about half as long. There are a lot of variables with chains though and you'll get a hundred differing opinions... So here's mine: XTR/XT chains are long lasting and shift the best. In recent years I've broken one Wipperman and one SRAM chain (neither at the connecting link so it wasn't install error) but no Shimano chains. It's not a scientific study but it's enough for me...

I treat my Shadow Plus like any other derailleur. Clean it off, check the bolts for tightness occasionally etc. It's a major improvement on a regular derailleur though. I dropped my chain from the big ring to the small (literally) once this year. With my XX double ring set up this was a constant concern when riding hard over rocky terrain crossed over in the "big/big" combo. Doesn't cross my mind now. I did manage to really wear out the lower jockey wheel though. The bearings are still good but a muddy marathon race recently wore the teeth to tiny points... no big deal though.

I've also been using XTR cassettes the last season and a half with great results. I've always been reluctant to "invest" in them as I hear they wear quickly and cost double the price of XT. I ride and race a lot and I'm impressed with the XTR cassette's durability. Certainly no worse than XT and loads better than the lousy SRAM (XO?) 11-36 units I replaced. The XTRs have survived quite a lashing including numerous muddy marathon races. I just did the muddiest seven hour race I can imagine. My new XT chain showed 1/2 wear at the finish. Put on a new chain later and the cogs are perfectly fine -- shift great and no skipping under load. I figured a season and a half of use, combined with this seven hour slopfest would finish it off. Nope. On my SRAM cassettes the 36 tooth cog wore out in half the time with half the use. Garbage. XTR chainrings seem to be holding up just as well. Thankfully!

Im getting the XTR cassette too for my race wheels and the cheaper cassette for my training wheels. I will keep my sram crankset though, will debadge the crank arms and will install raceface chainrings.

I really can't wait to get the stuff. My bike will be a complete rebuild for next season, only keeping the frame and fork. I invite you to follow the rebuild project in my Vertex 29er thread, linked in my signature.

Something else I forgot to mention is that I find the latest M980 XTR to have a very SRAM-like shifter feel. I really like this. The old M970 stuff just felt way too light and vague for me so I always used XO and then XX. Now XTR feels "clacky" and comes with Shimano durability and build quality. Can't go wrong.

But you can read many things on the net RE magnesium caliper: paint does not hold well onto it, it tends to overheat and has poor heat management capacity.

Shimano emphasizes the use of their IceTech rotor to help manage heat with their new magnesium brakes, so much that it sounds like the IceTech are very important to this particular brake set performance.

If there was any review on the net about these brakes and regular third party rotors, I'd take the risk for sure. But I don't think many people have tried em yet.

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